The absorption and secretion of water and electrolytes across the healthy and the diseased human colonic mucosa measured in vitro

Abstract

SUMMARY An 'in-vitro' technique is described for measuring quantitatively the absorption and secretion of water and electrolytes, the short circuiting current, and the simultaneous bidirectional flux rates of ions across the healthy and diseased colonic mucosa. The results show that the normal colon absorbs both sodium and water and secretes potassium.In (1951), to measure the net transport and simultaneous bidirectional flux rates of water and electrolytes across the human colonic epithelium studied in vitro. This method allows a direct measure of electrolyte transfer to be made in relation to mucosal surface area. It also permits an assessment of the electrical activity generated across the mucosa, and enables an analysis of some of the factors which may influence it. Materials and MethodsThe apparatus (see Fig.) consists of two identical perspex chambers between which is mounted a flat sheet of colonic mucosa. The dependent part of each chamber incorporates a Y-shaped inlet adjacent to the mucosa. Through one limb of this connexion

Upregulation of CFTR expression but not SLC26A3 and SLC9A3 in ulcerative colitis

“…Little is known about the possible role of electrolytetransport abnormalities in the pathogenesis of diarrhea associated with chronic intestinal inflammation (3,4,7,44). In animal models, colitis has been associated with a reduced expression of SLC26A3 and unchanged SLC9A3 (52).…”

“…CLD is a recessively inherited intestinal disorder that manifests with massive losses of Cl Ϫ in stools with respective defects in intestinal HCO 3 Ϫ secretion. As a result, the intestinal content is acidic, with corresponding systemic metabolic alkalosis.…”

Demonstration of active potassium transport in the mammalian colon.

“…Separate studies using colonic mucosa of man, rabbit, and pig, in which unidirectional fluxes of K were measured under short-circuited conditions have reported small, statistically significant, net secretion, compared to zero; a result that is consistent with active K secretion (3)(4)(5)(6). In addition, in studies with human tissue net K secretion was abolished in a Na-free media suggesting a possible link between Na and K transport (6).…”

“…Received for publication 25 April 1980 and in revised form 17 November 1980. in several species, in the absence ofelectrical gradients, have shown either no evidence of active K transport (1,2) or small, but statistically significant net, and presumably active, K movement (3)(4)(5)(6). There have been no in vivo studies performed under conditions that permit distinction between active and passive driving forces.…”

Activation of proteinase-activated receptor-1 inhibits neurally evoked chloride secretion in the mouse colon in vitro

“…Secretion of fluid into the lumen of the intestine serves, among other functions, to flush away potentially harmful luminal contents and thus slows or prevents the translocation of bacteria and antigens into the lamina propria of the intestine (2,47). The disruption of secretory function is characteristic of models of intestinal inflammation (2,17,27) and is observed in human IBD (1,22,33). The altered regulation of secretory function may in turn contribute to inflammatory conditions of the gut (2, 3).…”